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| author | Jason Wang <jasowang@redhat.com> | 2013-03-19 12:36:56 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-04-05 10:16:39 -0700 |
| commit | d1cc80b94858666cc48467e8e166ccf389551b5d (patch) | |
| tree | 2e6c9019568b282fe3522989638ac8752028d426 /drivers/net | |
| parent | 8868daebc1b6240d07d5c6428f8bc8631b2bed42 (diff) | |
| download | lwn-d1cc80b94858666cc48467e8e166ccf389551b5d.tar.gz lwn-d1cc80b94858666cc48467e8e166ccf389551b5d.zip | |
macvtap: zerocopy: validate vectors before building skb
commit b92946e2919134ebe2a4083e4302236295ea2a73 upstream.
There're several reasons that the vectors need to be validated:
- Return error when caller provides vectors whose num is greater than UIO_MAXIOV.
- Linearize part of skb when userspace provides vectors grater than MAX_SKB_FRAGS.
- Return error when userspace provides vectors whose total length may exceed
- MAX_SKB_FRAGS * PAGE_SIZE.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Benjamin Poirier <bpoirier@suse.de> [patch reduced to
the 3rd reason only for 3.0]
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/macvtap.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 6696e56e6320..023b57e2f76b 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -552,6 +552,10 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, if (unlikely(len < ETH_HLEN)) goto err; + err = -EMSGSIZE; + if (unlikely(count > UIO_MAXIOV)) + goto err; + skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, len, vnet_hdr.hdr_len, noblock, &err); if (!skb) |